Objective: This study aimed to estimate the prevalence of asthma-like symptoms, current asthma (CA), asthma diagnostic tests, and inhaled medication use in a nationwide pediatric population (<18 years). Methods: Pediatric-specific data from a cross-sectional, population-based telephone survey (INAsma study) in Portugal were analyzed. CA was defined as lifetime asthma and (1) wheezing, (2) waking with breathlessness, or (3) asthma attack in the previous 12 months, and/or (4) taking asthma medication at the time of the interview. Results: In total, 716 children were included. The prevalence of asthma-like symptoms was 39.4% [95% confidence interval (95% CI): 35.7–43.3]. The most common symptoms were waking with cough (30.9%) and wheezing (19.1%). The prevalence of CA was 8.4% (95% CI: 6.6–10.7). Among children with CA, 79.9% and 52.9% reported prior allergy testing and pulmonary function testing (PFT), respectively. Inhaled medication use in the previous 12 months was reported by 67.6% (reliever inhalers, 40.1%; controller inhalers, 41.5%). Those who only used inhaled reliever medications experienced more asthma attacks [odds ratio (OR): 2.69]. Significantly fewer children with CA living in rural areas than those living in urban areas had undergone PFT or used inhaled medication (OR: 0.06 for PFT, 0.20 for medication]. Conclusions: The prevalence of CA in the Portuguese pediatric population was 8.4%. Only half of children with CA had ever undergone PFT; more than half did not use controller inhalers, and those who only used reliever inhalers reported more asthma attacks. These findings suggest that asthma management has been substandard, mainly in rural areas.